I. Field
The present application relates generally to wireless communications, and more specifically to methods and systems to enable Media Access Control (MAC) based High-Speed Packet Access (HSPA) fast cell switching within a network.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power, etc.). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), High Speed Packet (HSPA, HSPA+), and others. Moreover, wireless communication systems can be designed to implement one or more standards, such as IS-95, CDMA2000, IS-856, W-CDMA, TD-SCDMA, and the like.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. In such a system, each terminal can communicate with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link can be established via a single-in-single-out (SISO), multiple-in-signal-out (MISO), or a multiple-in-multiple-out (MIMO) system.
An access terminal operating in a wireless communication system can change from the coverage of a first (e.g., source) cell to the coverage of a second (e.g., target) cell using a handover operation. For example, a terminal can initiate communications to request, and subsequently establish a connection with the target cell during a handover. With respect to the HSPA serving cell change procedure, particular concerns have been raised both in terms of reliability and latency. Moreover, it is unclear if the existing HSPA procedure can provide a sufficient grade of service for low latency real-time applications such as voice. Since it is anticipated that most voice traffic will be carried over HSPA in the future, it would thus be desirable to have a low-latency method and apparatus for reliably switching HSPA serving cells.